resolving symbolic links).

The special pattern <buffer> or <buffer=N> is used for buffer-local
autocommands |autocmd-buflocal|.  This pattern is not matched against the name
of a buffer.

Examples: >
	:autocmd BufRead *.txt		set et
Set the 'et' option for all text files. >

	:autocmd BufRead /vim/src/*.c	set cindent
Set the 'cindent' option for C files in the /vim/src directory. >

	:autocmd BufRead /tmp/*.c	set ts=5
If you have a link from "/tmp/test.c" to "/home/nobody/vim/src/test.c", and
you start editing "/tmp/test.c", this autocommand will match.

Note:  To match part of a path, but not from the root directory, use a "*" as
the first character.  Example: >
	:autocmd BufRead */doc/*.txt	set tw=78
This autocommand will for example be executed for "/tmp/doc/xx.txt" and
"/usr/home/piet/doc/yy.txt".  The number of directories does not matter here.


The file name that the pattern is matched against is after expanding
wildcards.  Thus if you issue this command: >
	:e $ROOTDIR/main.$EXT
The argument is first expanded to: >
	/usr/root/main.py
Before it's matched with the pattern of the autocommand.  Careful with this
when using events like FileReadCmd, the value of <amatch> may not be what you
expect.


Environment variables can be used in a pattern: >
	:autocmd BufRead $VIMRUNTIME/doc/*.txt  set expandtab
And ~ can be used for the home directory (if $HOME is defined): >
	:autocmd BufWritePost ~/.config/nvim/init.vim   so <afile>
	:autocmd BufRead ~archive/*      set readonly
The environment variable is expanded when the autocommand is defined, not when
the autocommand is executed.  This is different from the command!

							*file-pattern*
The pattern is interpreted like mostly used in file names:
	*	matches any sequence of characters; Unusual: includes path
		separators
	?	matches any single character
	\?	matches a '?'
	.	matches a '.'
	~	matches a '~'
	,	separates patterns
	\,	matches a ','
	{ }	like \( \) in a |pattern|
	,	inside { }: like \| in a |pattern|
	\}	literal }
	\{	literal {
	\\\{n,m\}  like \{n,m} in a |pattern|
	\	special meaning like in a |pattern|
	[ch]	matches 'c' or 'h'
	[^ch]   match any character but 'c' and 'h'

Note that for all systems the '/' character is used for path separator (even
Windows). This was done because the backslash is difficult to use in a pattern
and to make the autocommands portable across different systems.

It is possible to use |pattern| items, but they may not work as expected,
because of the translation done for the above.

							*autocmd-changes*
Matching with the pattern is done when an event is triggered.  Changing the
buffer name in one of the autocommands, or even deleting the buffer, does not
change which autocommands will be executed.  Example: >

	au BufEnter *.foo  bdel
	au BufEnter *.foo  set modified

This will delete the current buffer and then set 'modified' in what has become
the current buffer instead.  Vim doesn't take into account that "*.foo"
doesn't match with that buffer name.  It matches "*.foo" with the name of the
buffer at the moment the event was triggered.

However, buffer-local autocommands will not be executed for a buffer that has
been wiped out with |:bwipe|.  After deleting the buffer with |:bdel| the
buffer actually still exists (it becomes unlisted), thus the autocommands are
still executed.

==============================================================================
7. Buffer-local autocommands	*autocmd-buflocal* *autocmd-buffer-local*
				*<buffer>* *<buffer=N>* *<buffer=abuf>* *E680*

Buffer-local autocommands are attached to a specific buffer.  They are useful
if the buffer does not have a name and when the name does not match a specific
pattern.  But it also means they must be explicitly added to each buffer.

Instead of a pattern buffer-local autocommands use one of these forms:
	<buffer>	current buffer
	<buffer=99>	buffer number 99
	<buffer=abuf>	using <abuf> (only when executing autocommands)
			|<abuf>|

Examples: >
    :au CursorHold